Veil-Fail ....... What went wrong?

[steppenwolf]

The enclosed image was taken last night (250807) using a Tamron 100mm telephoto/macro lens on my SXVF-H9C with a 13Nm Ha Filter. The Moon was up and there was a fairly milky sky but I had expected the Ha filter to do a better job than this. In particular I am disappointed by the brightness gradient (dark at left, light at right) as, assuming that this is to do with the Moon, I had expected the Ha filter to have filtered this out.

Any suggestions as to what may have gone wrong?

[CELESCOPE]

dont think u was doing anything wrong Steve , the image on my screen of the veil was very faint. its normally a lot better so had to use DDP and some hard processing to get my image out, so dont alter anything , it was the conditions last night , , not the best mate

Rog

[Andrew*]

wrong?!? I see nothing wrong! That's a really nice image as far as i can work out!

Andrew

[centroid]

I don't think you could have done any different Steve.

At Mag 30 the 'Veil' is vey feint, as you know, and given how bright the Moon was last night, I reckon that the 'Veil' disappeared into the 'milky sky', despite the filter.

Dave

[blinky]

MAG 30 :shock: :shock: And you imaged it, thats amazing in my book

[steppenwolf]

Thanks for your comments and advice folks - I guess the Moon won this one then!

[bern]

Steve,

I think there's a few things going on in your image.

I can see some vignetting which can be dealt with in processing or reduced by stopping down.

Also dichroic filters are quite sensitive to positioning and F stop depending on how they're used. I've not done too many tests on this but have seen a similar effect when I used a UHC filter in front of a 50mm lens.

bern

[steppenwolf]

I can see some vignetting which can be dealt with in processing or reduced by stopping down.

Also dichroic filters are quite sensitive to positioning and F stop depending on how they're used.

I decided against vignetting as it is all off to one side and my sensor is pretty small - I don't have this problem with either an 50mm or 200mm lens which are, of course, either side of the 100mm focal length used here but this was a Tamron lens (other two are Canon) so the cone of 'light' could be very different from the other two lenses. In any event, you could well be right in that it could just be this particular focal length that is the problem.

With regard to your second point, I have heard this before but not looked into the 'mechanics' of it - I must do so.

Thanks, Bern.

[Astroman]

The Veil is close to the "edge" of the densest part of our galaxy. You've captured the "thinning" of stars near this boundary. It's a terrific shot!

Where'd you get the mag 30 number, Centroid? I believe this would be the overall surface brightness, when added up over the extent of the entire SN remnant. The faintest "main" components are mag 8 overall, with the fainter parts ~11 or so.